This Core comprises 16 members from five departments and three schools: Rutgers University, UMDNJ-Robert Wood Johnson Medical School and the UMDNJ-School of Public Health. The members represent a broad spectrum of physical, biomedical and engineering scientists sharing a common goal of measuring and modeling exposure of humans and animals to environmental toxicants and in examining the effects of these exposures on health of children and selected adult populations. The goals are, a) to conduct environmental exposure and environmental health studies among high risk children and adult populations; b) to conduct controlled exposure studies to determine physiological and psychological predictors and outcomes of ambient level exposures; c) to develop exposure?dose models from the populations to the tissue level; d) to develop and employ physical, chemical and biological markers of exposure and/or effect; and e) to integrate the results of exposure characterization and estimation into the development of basic toxicological research. There are three themes in this core. They are, Exposures of Children and High-Risk Adult Populations, Effects of Controlled Exposures, and Source-to-Dose Modeling.